Lead is a common heavy metal contaminant in the environment, which causes serious damage to the human health when exceeding the tolerable concentrations. Many studies have shown that lead is not an essential element for many organisms, but it can interact with biological macromolecules, and then interfere with the normal physiological functions. A large number of researchers had already studied the interaction of small molecules. For example, Kandagal et al. have studied the interaction between drug doxepin and human serum albumin, and Xu et al. have investigated the binding of pesticide phenthoate to bovine serum albumin . Currently, the molecular interactions between proteins and many heavy metal ions have been investigated successfully, for example Lead, Chromium, Nickel and so on. Hemocyanin (Hc) plays an important role as dioxygen carriers in the hemolymph of many molluscs and arthropods. Interest in the molluscan Hc is based primarily on the unique immunostimulatory properties of KLH, which is a high molecular weight, copper-containing protein found in the sea mollusk Megathura crenulata. KLH is used to be as an immunotherapeutic agent for the treatment of certain types of cancer and for the diagnosis of Schistosomiasis.